1. Field of the Invention
This application relates in general to a panel module and in particular to a panel module with two substrates having a constant distance therebetween.
2. Description of the Related Art
Referring to FIGS. 1A and 1B, a conventional touch panel usually comprises a first substrate 11 and a second substrate 12. During assembly, an LOCA 13 (liquid optical clear glue) is disposed between the first and second substrates 11 and 12 and cured by UV light, so as to firmly connect the first substrate 11 with the second substrate 12.
However, since the LOCA 13 can flow and form an uneven surface, an air gap 131 may be formed between the first and second substrates 11 and 12. Thus, bending and deformation of the first and second substrates 11 and 12 may occur and lead to a non-uniform distance therebetween. Generally, the distance between the first and second substrates 11 and 12 near the center thereof is smaller than that near the edge thereof. In practical applications, such as in the production of 3.5 inches touch panels, the variation of the distance may exceed 30%.
In capacitive touch panels, non-uniform distances between the first and second substrates 11 and 12 can adversely affect accuracy of capacitance sensing. For the reasons described above, the task of preventing non-uniform distances from occurring between the first and second substrates during assembly, has become a challenge.